package com.hope;

import android.support.v4.app.DialogFragment;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentManager.OnBackStackChangedListener;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class MainActivity extends FragmentActivity implements OnBackStackChangedListener {
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    private String[] navTitles;
    static Fragment visible_fragment;
    static android.app.Fragment prefFragment;
    static FragmentManager fragmentManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mTitle = mDrawerTitle = getTitle();
        navTitles = getResources().getStringArray(R.array.nav_buttons);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        // set a custom shadow that overlays the main content when the drawer opens
        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
        // set up the drawer's list view with items and click listener
        mDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, navTitles));
        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        // enable ActionBar app icon to behave as action to toggle nav drawer
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
        
        //Listen for changes in the back stack
        getSupportFragmentManager().addOnBackStackChangedListener(this);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the sliding drawer and the action bar app icon
        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  /* host Activity */
                mDrawerLayout,         /* DrawerLayout object */
                R.drawable.ic_drawer,  /* nav drawer image to replace 'Up' caret */
                R.string.drawer_open,  /* "open drawer" description for accessibility */
                R.string.drawer_close  /* "close drawer" description for accessibility */
                ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            selectItem(0);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main, menu);
        return super.onCreateOptionsMenu(menu);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action buttons
        switch(item.getItemId()) {
        case android.R.id.home:
        	if (getSupportFragmentManager().getBackStackEntryCount() > 0)
        		getSupportFragmentManager().popBackStack();
        	else
        		mDrawerToggle.onOptionsItemSelected(item);
        	return true;  
        case R.id.action_websearch:
            DialogFragment emergencyDialog = new EmergencyDialog();
            emergencyDialog.show(getSupportFragmentManager(), "emergency");
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

    /* The click listener for ListView in the navigation drawer */
    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    private void selectItem(int position) {
        // update the main content by replacing fragments
        Fragment fragment = null;
        switch (position) {
        case 0: fragment = new DailyPill();
        	break;
        case 1: fragment = new PillCalendar();
    		break;
    	case 2: fragment = new PillInventory();
    		break;
    	case 3: fragment = new AddNewPill();
    		break;
    	case 4: prefFragment = new Settings();
    		break;
        }

        fragmentManager = getSupportFragmentManager();
        if (fragment != null) {
        	if (prefFragment != null) {
        		getFragmentManager().beginTransaction().remove(prefFragment).commit();
        	}
        	fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
        } else {
        	if (visible_fragment != null) {
        		fragmentManager.beginTransaction().remove(visible_fragment).commit();
        	}
        	getFragmentManager().beginTransaction().replace(R.id.content_frame, prefFragment).commit();
        }
        visible_fragment = fragment;

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        setTitle(navTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getActionBar().setTitle(mTitle);
    }

    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }
    
    @Override
    public void onBackStackChanged() {
    	int backStackEntryCount = getSupportFragmentManager().getBackStackEntryCount();
    	if(backStackEntryCount > 0){
    		mDrawerToggle.setDrawerIndicatorEnabled(false);
    	}else{
    		mDrawerToggle.setDrawerIndicatorEnabled(true);
    	}
    }
}